The Many Layers of Soil

1. The Many Layers of Soil

2. Objectives The students will: Define the soil class system Identify the 6 soil layers found in Louisiana Define one characteristic of each layer Distinguish between most intensive use and profit vs. land impact

3. Soil Taxonomy

4. Soil Taxonomy Utilizes the concepts of soil as natural bodies Based on observable and measurable soil properties Employs a unique nomenclature that connotes the major characteristics of the soils in question.

5. Why Classify Soils? Need to make proper land use decisions Need to know what kind of soil this is Need to distinguish one soil from another Communicate with each other about the different soils

6. Why Classify Soils Cont…?Profit Vs. Land Impact PROFIT When is making money more important than living on the land? LAND IMPACT Leaching of important nutrients Nonpoint pollution No-Till Method Organic mulches – good or bad

7. Soil Taxonomy Categories Order Suborder Great Group Subgroup Family Series

8. Soil Order All soils belong to one of the twelve soil orders which are differentiated from each other primarily by the presence or absence of specific diagnostic horizons. We will review the soils that are located in Louisiana.

9. Inceptisols More development then Entisols Weak B horizon Found in cold, waterlogged climates Few diagnostic features

10. Mollisols Soft, organic rich surface Grassland soils Thick A horizons High OM Very fertile

11. Alfisols Aluminum, Iron and clay found in B horizon Typically (deciduous) forest soils Humid and subhumid climates Water availability much of the growing season

12. Spodisols Grey color of E horizon Sandy and acid forest soils (conifers) High leaching

13. Vertisols High shrink-swell clay content Display deep cracks when dry Found in temperate to tropical climates Very distinct wet and dry season

14. Ultisols Thick A horizon Found in forest vegetation soils Similar to Alfisols but contain more weathered minerals

15. Oxisols Highly oxidized throughout profile Highly weathered Mostly Al and Fe oxides Low fertility Sometimes can be found in northern Louisiana

16. Histosols Very organic soils 20% OM at a minimum Develop in wet, cold climates Bogs, marshes and swamps

17. Now it’s time to match the land…. Write the name down of the land usage.

18. Very organic soils Develop in wet, cold climates

19. Highly oxidized Low fertility

20. High shrink swell clay content Displays deep cracks when dry

21. Weak B horizon Found in cold, waterlogged climates

22. Highly weathered Mostly Al and Fe oxides

23. Most recent soil development A horizon only

24. What is a Soil Survey Map? Soil surveys: Classify Locate Describe

25. Land Capability Classes Land Capability Classes distinguish soils according to their suitability for agriculture uses. There are eight classes available for use.

26. Land Capability Classes Class I – are suited for cultivation over a long period of time and have no limitations that restrict their use. They are deep, nearly level, moderately permeable, and subject to no more than slight erosion. Class II - are suited for cultivation over a long period of time, but they have some hazards and limitations such as gentle slope, slight erosion, or moderate wetness that reduce the choice of plants or require moderate conservation practices that are easy to apply.

27. Land Capability Classes Cont.. Class III - good for cultivated crops, but have severe limitations that reduce the choice of plants and/or require special conservation practices that are more difficult to apply. Terracing and other water control measures will be needed. Class IV - can be cultivated, but they have very severe limitations that restrict the choice of plants, require very careful management, special conservation, or both. They are sloping, moderately eroded soils with poor characteristics. Cultivated areas should be strip tilled, terraced, and farmed on the contour. They are best suited for pasture and range.

28. Land Capability Classes Cont.. Class V - have little or no erosion hazards, but have other limitations that make them unsuitable for cultivation. Limitations are impractical and very expensive to remove and limits their use to pasture, range, woodland, or wildlife food and cover. Limitations include very poor surface and internal drainage or frequent flooding. (Frequent flooding will be shown with “other factors” when it occurs.) Class VI —have severe limitations such as steep slopes, severe erosion, shallowness, and rockiness that make them generally unsuited for cultivation and limits their use to pasture or range, woodland, or wildlife food and cover.

29. Land Capability Classes Cont.. Class VII —have many very severe limitations similar to Class VI that make them unsuited for cultivation and that restrict their use to grazing, woodland, or wildlife. Class VIII —have limitations that preclude their use for crop, pasture, or timber production and restrict their use to wildlife, recreation, or aesthetics. This land has little or no economic value.

30. Soil Survey Maps A soil survey is a detailed report on the soils of an area. The soil survey has maps with soil boundaries and photos, descriptions, and tables of soil properties and features. Soil surveys are used by farmers, real estate agents, land use planners, engineers and others who desire information about the soil resource

31. Mapping A Soil Area Soil Scientist walks the land. Frequently stops and probes the land. The scientist takes notes on slope, erosion and other interesting factors. The surveyor draws the soil map The NRCS takes aerial photographs on the base map GPSs systems are currently being used.

32. Link to Land Surveys http://soils.usda.gov/survey/online_surveys/louisiana/

33. Land Judging Competition Held annually in November 4 person team – lowest score dropped There are seven different areas on the soil card: Texture Slope Permeability Depth Erosion Runoff Classes

34. Land Judging….Please use the following websites to train your team http://www.landjudging.com/2009/land_judging_manual_2009.pdf http://www.laffa.org/main/index.php?option=com_content&view=article&id=60&Itemid=59

35. GOOD LUCK ?